Tubes,more particularly for erecting tubular frameworks



Feb. 1o,- 1970 TUBES`, MORE PARTI Ci-Jl'vf'ARl'JY FOR ERECTING 'II'.'UBUIJAR4 FRAMEWORKS original Filed Dec. 11; 1116s` 4 Sheets-Sheet 1 mf Il INVENTOR JAcouEs-Luclen JEAN vaurms SYM ATTORNEYS Feb. 10, 1970 J; L. J. vALLElNs 3,494,170

TUBES, MORE PARTICULARLY FOR ERCTING TUBULAR FRAMEWORKS Original Filed Dec. l1, 1963 4 Sheets-Sheet 2 lNvE'NoR JACQUES LUCIEN JEAN VLLEINS lr1n/4/ffrlvflllllalllllllffllaifrfrlllllrllllfll//IC frfrfllllllfn.

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Air TORNEYS TUBES, MORE PARHCULARLY Fon ERECTINQTUBULAR FnAMEwonKs original Fild Dec.

J. L. J. vALLElNs Feb. 1970 4 Sheets-Sheet 5 IN V E N T 0 Jncos Lucnan JEAN vALLEms BY y T T0 RNEYS Feb. 10, 1970 J. l., J. vALLElNs .Y 3,494,170

TUBES, MORE PARTICULARLY FOR IVIRECTING 'IUBULAR4 FRAMEWORKS Original Filed Dec. 1l. 1963 4 Sheets-.Sheet 4.

Fig. 7

I N V E N TOR `:Acoulis LuclEN JEAN VALLEINS www ATTORNEYS United States im. ct. nztd 41/04 ABSTRACT F THE DISCLOSURE Apparatus for making metal tubes of square or rectangular cross-section having ribs or utings swaged thereon spaced at regular intervals comprising, in combination, a press for preferably operating simultaneously on two opposite faces of the tube, and a mandrel insertable into said tube, said mandrel having dies mounted pivotably thereon, cooperating with 'said press, and disengageable o s. ct. 'rz- 398 v s claims from the internal tube faces whereby a longitudinal dis-V placement of said tube with respect to said mandrel can occur between swaging operations.

This application is a division' of copending U.S. patent application Ser. No. 329,758, fledDec.y 1l, 1963, now abandoned. 1 p f It is well known that tubes of square or rectangular crossfsection facilitate the assembly of tubular frameworks. 0n the other hand, the flat faces of such tubes are prone to sustain local distortions due to crippling or punching'.

It is the chief aim of the present invention to overcome such drawbacks.

The invention accordingly has for its object a tube of square or rectangular cross-section` of whichat least one face, and preferably two' opposite faces or possibly all four faces, embody swaged fiutngs spaced at regular intervals over a portion at least of the length of the tube.

Such swaged utings reinforce the tubefaces on which they are provided and their shape could be such as to liken such tube faces towhat is common practice in the art of structural steelwork yand metal frameworksmamely lattice girders of Virsandel girders.

In cases where a local force tending to distort one of the at uted faces is applied, its action'tends to be transmitted by the utings, whose shape is particularly appropriate for withstanding transverse compression forces in particular.

ihe utings are swaged inwardly into the tube, in consequence whereof the external face of the tubev is devoid of raised portions, thus enabling flat surfaces to be joined together.

The utng are obtained during manufacture ofthe tubes andthe-ir shape can vary greatly. For instance, they could be perpendicular to the axis of the ltube or be inclined relative thereto in the same direction or in alternating directions, or else they could be circular or rectangular. These iiutings can be obtained with advantage by swaging industrial-type tubes, whose face usually have a width in excess of 150 millimetres.

The depth of a swaging whichdepends on thethickness of the sheet-metal could beof the order of 1,4 of the width of the tube-face and its width could be equal to approximately one-tenth, say, of the width of the tube face.

Furthermore, the pitch, i.e. the mean distance between two consecutive utngs, as measured parallel with the tube axis, is substantially equal to the width of the tube face. Considering finally the tube itself, its length is im- 3,494,17@ Patented Feb. l0, 1970 material, being for all practical purposes limited only by transport considerations. As stated precedingly, it may be preferable in certain cases to restrict the tlutings to part only of the tube length.

The invention likewise encompasses apparatus for stamping utings on industrial-type tubes of square orrectangular cross-section whereby to obtain the tinted tubes referred to hereinabove.

Such apparatus comprises basically a press that preferably operates on two opposite faces of the tube simultaneously, and a mandrel engaging into the tube. The mandrel supports dies and is devised to enable the same to be applied against the internal faces of the tube for cooperation with the press whereby to obtain the swagings and also to enable said dies to be disengaged from the internal faces of the tube after the swagings have been performed in order that the tube can be moved longitudinally relative to the mandrel and thereby enable a fresh swaging operation to commence.- z

In one vform of embodiment of the invention, the mandrel comprises two yokes each having a die pivotally mounted thereon. The two yokes are interconnected a't` one end by an elastic member, and the spreading apart of the two yokes that causes said dies to be applied against the internal faceslof the tube, as well as the subsequent contraction of the yokes that enablesthe dies to be disengaged from the' tube faces, are obtained by means of a` wedge-shaped axial member which is adapted to be insertable between said yokes and to be movable in reciprocation relative thereto( The description which follows with reference to the accompanying nonflimitative exemplary drawing will give a clear understanding of how the yinvention can be carried into effect. y

`Referring to the drawing filed herewith:

FIGURES l to 6 show schematically in longitudinal axial'section apiece of apparatus for performing the desred swagings on a tube, said figures illustrating the respective positions of the various component parts inthe course of a swaging cycle, and

FIGURES 7 to 1l show diagrammatcally tubes embodying different types of utings.

In FIGURES l .to`6, reference numeral 1 designates an industrial-type metal tube of square or rectangular section, onto two of the faces of which it is desired to stamp utings by means of a press whose operative components are schematically represented at 2a.

Reference numeral` 3 denotes the mandrel which is inserted into the tube and comprises two yokes 4 and 4a having one of their ends pivotally connected at 5 and 5a to the body proper of the mandrel, which mandrel is a holow core-piece whose outer diameter is substantially less than the internal dimensions of the tube. The other ends of yokes 4 and 4o are interconnected by a spring 6.

Each arm supports a shaft 7 (or 7a) parallel to the corresponding tube face into which the lluting or set of timings is to be swaged. Dies 8 and 8a adapted to cooperatewith the press members 2 and v2a` are pivotally mountedon shafts 7 and 7a.

Between the yokes 4 and 4u is slidable a wedge-shaped member 9 having thereon inclined faces l0 and 10a adapted to cooperate with internal die faces of identical inclination 1l and lla. Said member terminates in a tapered head l2.

The swaging apparatus of this invention operates in the following manner.

With the wedge-shaped member 9 in the retracted position relative to the yokes 4 and 4a, the mandrel is inserted into the tube until the dies are level with the press members 2 and 2a (see FIGURE l), penetration of the mandrel into the tube being possibleby reason of the maxi mum contraction thereof.

The wedge-shaped member 9 is then slid forward be tween the yokes 4 and 4a, thereby causing the latter to spread apart and the dies 8 and 8a to be applied against the internal faces of tube 1. As the wedge-shaped member 9 slides forward, its head 12 penetrates between the eX- tremities of the yoke arms (see FIGURE 2). The penetrating motion of the Wedge-shaped member 9 is pursued until its inclined faces 10 and 10a come into pressure contact with the corresponding inclined faces 11 and 11a of the dies. A rigid assembly inside the tube is thus obtained (see FIGURE 3).

The pressure exerted by the press members 2 and 2a causes the desired ilutings to be swaged against the dies 8 and 8a, which dies are rigidly buttressed against the member 9 (see FIGURE 4).

It is to be noted that the slope of the faces 10, 10a, 1l and 11a is chosen so that the coefficients of friction between the various parts involved be suflicient to prevent the wedge-shaped member from being ejected during the swaging operation, but it will be manifest that the Wedgeshaped member could be suitably restrained, if desired, during the swaging operation.

Once the swaging operation has been effected, the wedge-shaped member 9 is retracted in order to disengage its faces 10 and 10a from the corresponding inclined die faces (see FIGURE 5).

The retracting motion of the wedge-shaped member is continued until the mandrel reverts to the configuration shown in FIGURE 1, thereby enabling the tube 1 and its swaged utings to be moved relative to the mandrel before it undergoes a fresh swaging operation (see FIG- URE 6).

It goes without saying that the various operations, and more specifically the movements of the Wedge-shaped member relative to the mandrel proper and of the tube relative to the mandrel, are obtained by conventional mechanisms that can be adapted to this particular funcn tion without difficulty by a specialist in the art.

Manifestly, the mandrel could support a plurality of sets of dies, or the dies could be of sufficient length to bear thereon a multiplicity of consecutive imprints.

It will of course be appreciated that if a press capable of operating over the entire length of a tube is to be used, it will suice to so adapt the mandrel that it coact with the press during the simultaneous swaging of -all the flutings. Alternatively, the flutings could be obtained by means of one or more rolling-mills in lieu of a press.

Irrespective of the method used, the tube flutings can be perpendicular to the tube axis as shown in FIGURE 7, oblique or cruciform as shown in FIGURES 8 and 9 re spectively, circular as shown in FIGURE l0, or rectangun lar as shown in FIGURE ll; alternatively, the tiutings could be of any other appropriate shape,

What is claimed is:

1. Apparatus for making tubes of rectangular crosssection, more particularly for use in structural frameworks, having, on at least one of its faces, ribs or flutings swaged thereon and spaced at regular intervals over at least part of the length of the tube comprising, in combination, a press for preferably operating simultaneously on two opposite faces of the tube, and a man drel insertable into said tube, said mandrel having dies mounted pivotably thereon and being so adapted that said dies ybe applicable against the internal tube faces for cooperation with said press for the swaging operation and disengageable from said internal tube faces subsequent to the swaging operation whereby to permit longitudinal displacement of said tube with respect to said mandrel and thereby to enable a fresh swaging operation to begin.

2. Apparatus as claimed in claim 1, wherein said mandrel comprises two yokes each having a die pivotally mounted thereon, said. two yokes having one of their ends pivotally connected to a central core-piece and being interconnected at their other ends through the agency of spring means.

3, Apparatus as claimed in claim 1 wherein said diebearing mandrel comprises two yokes having one of their ends pivotally connected to a central core-piece and having their other ends interconnected through spring means, and a Wedge-shaped axial member adapted to be driven between said two yokes and to be retracted therefrom in a reciprocating motion relative to said two yokes.

4. Apparatus as claimed in claim 3, wherein said Wedge-shaped member .has inclined faces adapted to c0- operate with inclined faces on said dies whereby to rigidly buttress the same during the swaging operation 5. .Apparatus as claimed in claim 4, wherein the slope of said inclined faces is chosen so that the coefiicient of friction `between the faces in Contact be sufficient to prevent said wedge-shaped member from being ejected during the swaging operation..

References Cited UNITED STATES PATENTS .5,143,794 8/1964 Martin-Hurst 72-370 3,263,474 8/1966 Pentland 72-370 MILTON S. MEHR, Primary Examiner US. Clo XLR, '72@-401 

